draft-ietf-secevent-token.xml

<?xml version="1.0" encoding="utf-8"?>
<?xml-stylesheet type='text/xsl' href='http://xml2rfc.tools.ietf.org/authoring/rfc2629.xslt' ?>
<!DOCTYPE rfc SYSTEM "rfc2629.dtd">

<?rfc toc="yes"?>
<?rfc tocompact="yes"?>
<?rfc tocdepth="3"?>
<?rfc tocindent="yes"?>
<?rfc symrefs="yes"?>
<?rfc sortrefs="yes"?>
<?rfc comments="yes"?>
<?rfc inline="yes"?>
<?rfc compact="yes"?>
<?rfc subcompact="no"?>

<rfc category="std" docName="draft-ietf-secevent-token-13" ipr="trust200902">
  <front>
    <title abbrev="draft-ietf-secevent-token">Security Event Token (SET)</title>

    <author fullname="Phil Hunt" initials="P." role="editor" surname="Hunt">
      <organization abbrev="Oracle">Oracle Corporation</organization>
      <address>
        <email>phil.hunt@yahoo.com</email>
      </address>
      
    </author>

    <author fullname="Michael B. Jones" initials="M.B." surname="Jones">
      <organization abbrev="Microsoft">Microsoft</organization>
      <address>
        <email>mbj@microsoft.com</email>
	<uri>http://self-issued.info/</uri>
      </address>
    </author>

    <author fullname="William Denniss" initials="W." surname="Denniss">
      <organization abbrev="Google">Google</organization>
      <address>
        <email>wdenniss@google.com</email>
      </address>
    </author>

    <author fullname="Morteza Ansari" initials="M.A." surname="Ansari">
      <organization abbrev="Cisco">Cisco</organization>
      <address>
        <email>morteza.ansari@cisco.com</email>
      </address>
    </author>

    <date year="2018" month="May" />

    <area>Security</area>
    <workgroup>Security Events Working Group</workgroup>

    <keyword>Identity</keyword>
    <keyword>Security</keyword>
    <keyword>Event</keyword>
    <keyword>Token</keyword>
    <keyword>Claims</keyword>
    <keyword>JSON</keyword>
    <keyword>JSON Web Token</keyword>
    <keyword>JWT</keyword>
    <keyword>Internet-Draft</keyword>

    <abstract>
      <t>
	This specification defines the Security Event Token (SET) data structure.
	A SET describes statements of fact from the perspective of an issuer
	about a subject. These statements of fact represent an event 
  that occurred directly to or about a security subject, for example,
  a statement about the issuance or revocation of a token on
  behalf of a subject. This specification is intended to enable 
  representing security- and identity-related events. A SET is a 
  JSON Web Token (JWT), which can be optionally signed and/or 
  encrypted. SETs can be distributed via protocols such as HTTP.
      </t>
    </abstract>
  </front>

  <middle>
    <section anchor="intro" title="Introduction and Overview" toc="default">
      <t>This specification defines an extensible Security Event Token 
      (SET) data structure, which can be exchanged using protocols such as HTTP.
      The specification builds on the JSON Web Token (JWT) format <xref target="RFC7519"/> 
      in order to provide a self-contained token that can be optionally 
      signed using JSON Web Signature (JWS) <xref target="RFC7515"/>
      and/or encrypted using JSON Web Encryption (JWE) <xref target="RFC7516"/>.</t>
      
      <t>This specification profiles the use of JWT for the purpose of 
      issuing Security Event Tokens (SETs). This specification defines a 
      base format used by profiling specifications to define actual 
      events and their meanings.
      This specification uses non-normative example events to 
      demonstrate how events can be constructed.</t>
      
      <t>This specification is scoped to security- and identity-related events.
      While Security Event Tokens may be used for other purposes, the specification
      only considers security and privacy concerns relevant to identity 
      and personal information.</t>
      
      <t>Security events are not commands issued between parties.
      A SET describes statements of fact from the perspective of 
      an issuer about a subject (e.g., a web resource, token, IP 
      address, the issuer itself). These statements of fact 
      represent a logical event that occurred directly to or about a 
      security subject, for example, a statement about the issuance 
      or revocation of a token on behalf of a subject. A security 
      subject may be permanent (e.g., a user account) or temporary
      (e.g., an HTTP session) in nature. A state change could 
      describe a direct change of entity state, an implicit change of state, 
      or other higher-level security statements such as:
      <list style="symbols">
        <t>The creation, modification, removal of a resource.</t>
        <t>The resetting or suspension of an account.</t>
        <t>The revocation of a security token prior to its expiry.</t>
        <t>The logout of a user session. Or, </t>
        <t>An indication that a user has been given control of an email identifier
	      that was previously controlled by another user.
	      </t>
      </list></t>
            
      <t>While subject state changes are often triggered by 
      a user agent or security subsystem, the issuance and transmission 
      of an event may occur asynchronously and in a back channel to
      the action that caused the change that generated the security 
      event. Subsequently, a SET recipient, having received a SET, 
      validates and interprets the received SET and takes its own 
      independent actions, if any. For example, having been informed of
      a personal identifier being associated with a different security 
      subject (e.g., an email address is being used by someone else), 
      the SET recipient may choose to ensure that the new user is not granted 
      access to resources associated with the previous user. Or, the 
      SET recipient may not have any relationship with the subject, 
      and no action is taken.</t>
      
      <t>While SET recipients will often take actions upon receiving 
      SETs, security events cannot be assumed to be commands or requests. 
      The intent of this specification is to define a syntax for
      statements of fact that SET recipients may interpret for their own
      purposes.</t>

      <section anchor="notat" title="Notational Conventions" toc="default">
	<t>
	  The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
	  "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED",
	  "MAY", and "OPTIONAL" in this document are to be interpreted as
	  described in BCP 14 <xref target="RFC2119"/> <xref target="RFC8174"/>
	  when, and only when, they appear in all capitals, as shown here.
	</t>

        <t>For purposes of readability, examples are not URL encoded.
        Implementers MUST percent encode URLs as described in
	Section 2.1 of <xref target="RFC3986"/>.</t>

        <t>Throughout this document, all figures may contain spaces and extra
        line-wrapping for readability and space limitations. Similarly, some
        URIs contained within examples have been shortened for space and
        readability reasons.</t>
      </section>

      <section anchor="defs" title="Definitions" toc="default">
        
        <t>
          The following definitions are used with SETs:
          <list style="hanging">
 
          <t hangText="Security Event Token (SET)">
	    <vspace/>
            A SET is a JWT <xref target="RFC7519"/> conforming to 
            this specification.
          </t>
          
          <t hangText="SET Issuer">
	    <vspace/>
            A service provider that creates SETs to be sent to other service providers known
            as SET recipients. 
          </t>
          
          <t hangText="SET Recipient">
	    <vspace/>
            A SET recipient is an entity that receives SETs through 
            some distribution method. A SET recipient is the same
            entity referred as a "recipient" in <xref target="RFC7519"/> or "receiver" in
            related specifications.
          </t>
            
          <t hangText="Subject">
	    <vspace/>
            A SET describes an event or state change that has occurred 
            to a subject. A subject might, for instance, be a principal (e.g., 
            Section 4.1.2 of <xref target="RFC7519"/>), a web resource,
            an entity such as an IP address, or the issuer of the SET.
          </t>

          <t hangText="Event Identifier">
	    <vspace/>
	    A member name for an element of the JSON object that is
	    the value of the <spanx style="verb">events</spanx> claim in a SET.
	    This member name MUST be a URI.
          </t>

          <t hangText="Event Payload">
	    <vspace/>
	    A member value for an element of the JSON object that is
	    the value of the <spanx style="verb">events</spanx> claim in a SET.
	    This member value MUST be a JSON object.
          </t>

          <t hangText="Profiling Specification">
	    <vspace/>
	    A specification that profiles the SET data structure to define
	    one or more specific event types and their associated claims and processing rules.
          </t>

          </list>
        </t>
      </section>
    </section>

    <section anchor="events" title="The Security Event Token (SET)">
      <t>
	A SET is a JWT <xref target="RFC7519"/> data structure that represents
	one or more related aspects of a security event that occurred to a subject.
	The JWT Claims Set in a SET has the following structure:
	<list style="symbols">
	  <t>
	    The top-level claims in the JWT Claims Set are called the SET "envelope".
	    Some of these claims are present in every SET;
	    others will be specific to particular SET profiles or profile families.
	    Claims in the envelope SHOULD be registered in the
	    "JSON Web Token Claims" registry <xref target="IANA.JWT.Claims"/> or be
	    Public Claims or Private Claims, as defined in <xref target="RFC7519"/>.
	  </t>
	  
	  <t>
	    Envelope claims that are profiled and defined in this specification
	    are used to validate the SET and provide information about
	    the event data included in the SET.
	    The claim <spanx style="verb">events</spanx> contains the event identifiers
	    and event-specific data expressed about the security subject.
	    The envelope MAY include event-specific or profile-specific data.
	    The <spanx style="verb">events</spanx> claim value MUST be a JSON object
	    that contains at least one member.
	  </t> 
	  
	  <t>
	    Each member of the <spanx style="verb">events</spanx>
	    JSON object is a name/value pair. The JSON member name is a
	    URI string value, which is the event identifier, and the
	    corresponding value is a JSON object known as the event "payload".
	    The payload JSON object contains claims that pertain to
	    that event identifier and need not be registered as JWT claims.
	    These claims are defined by the profiling specification that defines the event.
	    An event with no payload claims SHALL be represented as the empty JSON object 
	    (<spanx style="verb">{}</spanx>).
	  </t>
	  <t>
	    When multiple event identifiers are contained in a SET,
	    they represent multiple aspects of the same state transition
	    that occurred to the security subject.
	    They are not intended to be used to aggregate distinct events about the same subject.
	    Beyond this, the interpretation of SETs containing multiple event identifiers
	    is out of scope for this specification;
	    profiling specifications MAY define their own rules regarding their use of
	    SETs containing multiple event identifiers, as described in <xref target="Profiles"/>.
	    Possible uses of multiple values include, but are not limited to:
	    <list style="symbols">
	      <t>
		Values to provide classification information (e.g., threat type or level).
	      </t>
	      <t>
		Additions to existing event representations.
	      </t>
	      <t>
		Values used to link potential series of events.
	      </t>
	      <t>
		Specific-purpose event URIs used between particular SET issuers and SET recipients.
	      </t>
	    </list>
	  </t>
	  
	</list>
      </t>

      <section anchor="IllustrativeExamples"  title="Illustrative Examples">

	<t>
	  This section illustrates several possible uses of SETs
	  through non-normative examples.
	</t>

	<section anchor="SCIMExample" title="SCIM Example">

    <t>The following example shows the JWT Claims Set for a hypothetical 
    SCIM <xref target="RFC7644"/> password reset SET. Such
    a SET might be used by a receiver as a trigger to reset 
    active user-agent sessions related to the 
    identified user.</t>
        
      <figure anchor="examplePassword" title="Example SCIM Password Reset Event">
        <artwork>
{ 
  "iss": "https://scim.example.com",  
  "iat": 1458496025,
  "jti": "3d0c3cf797584bd193bd0fb1bd4e7d30",
  "aud": [
    "https://jhub.example.com/Feeds/98d52461fa5bbc879593b7754",
    "https://jhub.example.com/Feeds/5d7604516b1d08641d7676ee7"
  ],  
  "sub": "https://scim.example.com/Users/44f6142df96bd6ab61e7521d9",
  "events": {
    "urn:ietf:params:scim:event:passwordReset": 
      { "id": "44f6142df96bd6ab61e7521d9"},
    "https://example.com/scim/event/passwordResetExt": 
      { "resetAttempts": 5}
  }
}
</artwork>
      </figure>      
      <t>
	The JWT Claims Set usage consists of:
	<list style="symbols">

        <t>The <spanx style="verb">events</spanx> claim specifying the hypothetical 
        SCIM URN (<spanx style="verb">urn:ietf:params:scim:event:passwordReset</spanx>) 
        for a password reset, and a second value, 
        <spanx style="verb">https://example.com/scim/event/passwordResetExt</spanx>, 
        that is used to provide additional event information such as the 
        current count of resets.</t>

        <t>The <spanx style="verb">iss</spanx>
        claim, denoting the SET issuer.</t>

        <t>The <spanx style="verb">sub</spanx> claim, specifying the SCIM 
        resource URI that was affected.</t>

        <t>The <spanx style="verb">aud</spanx> claim, specifying the 
        intended audiences for the event.
	(The syntax of the <spanx style="verb">aud</spanx> claim
        is defined in Section 4.1.3 of <xref target="RFC7519"/>.)
        </t>
      </list></t>
      
      <t>The SET contains two event payloads:<list style="symbols">
        <t>The <spanx style="verb">id</spanx> claim represents
        SCIM's unique identifier for a subject.</t>
    
       <t>The second payload identified by <spanx style="verb">https://example.com/scim/event/passwordResetExt</spanx>)
       and the payload claim <spanx style="verb">resetAttempts</spanx>
       conveys the current count of reset attempts. In this example,
       while the count is a simple factual statement for the issuer, 
       the meaning of the value (a count) is up to the receiver.
       As an example, such a value might be used by the receiver 
       to infer increasing risk.
       </t>     
      </list></t>
      
 
      
      
      <t>In this example, the SCIM event 
      indicates that a password has been updated and the current 
      password reset count is 5. Notice that the value for 
      <spanx style="verb">resetAttempts</spanx> is in the event payload
      of an event used to convey this information.  
      </t>

	</section>

	<section anchor="LogoutExample" title="Logout Example">

      <t><figure anchor="exampleBackLogoutEvent" title="Example OpenID Back-Channel Logout Event">
            <preamble>Here is another example JWT Claims Set for a security event token, this one
              for a Logout Token:</preamble>

            <artwork>
{
   "iss": "https://server.example.com",
   "sub": "248289761001",
   "aud": "s6BhdRkqt3",
   "iat": 1471566154,
   "jti": "bWJq",
   "sid": "08a5019c-17e1-4977-8f42-65a12843ea02",
   "events": {
     "http://schemas.openid.net/event/backchannel-logout": {}
   }
}
</artwork>
          </figure>
	  </t>
	  <t>
	    Note that the above SET has an empty JSON object and
          uses the JWT claims <spanx style="verb">sub</spanx> 
          and <spanx style="verb">sid</spanx> to identify the subject
          that was logged out.
	    At the time of this writing, this example
	    corresponds to the logout token defined in the
	    <xref target="OpenID.BackChannel">OpenID Connect Back-Channel Logout 1.0</xref>
	    specification.
	  </t>

	</section>

	<section anchor="ConsentExample" title="Consent Example">

          <t>
          <figure anchor="exampleConsent" title="Example Consent Event">
        <preamble>In the following example JWT Claims Set, a fictional medical service collects 
          consent for medical actions and notifies other parties. The individual
          for whom consent is identified was originally authenticated via
          OpenID Connect.  In this case, the issuer of the security event is an
          application rather than the OpenID provider:</preamble>
        <artwork>
{ 
  "iss": "https://my.med.example.org",  
  "iat": 1458496025,
  "jti": "fb4e75b5411e4e19b6c0fe87950f7749",
  "aud": [
    "https://rp.example.com"
  ],  
  "events": {
    "https://openid.net/heart/specs/consent.html": {
      "iss": "https://connect.example.com",
      "sub": "248289761001",
      "consentUri": [
        "https://terms.med.example.org/labdisclosure.html#Agree"
      ]
    }
  }
}
</artwork>
      </figure>
	  </t>
	  <t>
      In the above example, the attribute <spanx style="verb">iss</spanx> contained within the
      payload for the event <spanx style="verb">https://openid.net/heart/specs/consent.html</spanx> refers
      to the issuer of the security subject (<spanx style="verb">sub</spanx>) rather than the
      SET issuer <spanx style="verb">https://my.med.example.org</spanx>. They are
      distinct from the top-level value of <spanx style="verb">iss</spanx>,
      which always refers to the issuer of the event -- a medical consent
      service that is a relying party to the OpenID Provider.
          </t>

	</section>

	<section anchor="RISCExample" title="RISC Example">

          <t>
	    <figure anchor="exampleRISC" title="Example RISC Event">
	      <preamble>
		The following example JWT Claims Set is for an account disabled event.
		This example was taken from a working draft of the RISC events specification,
		where RISC is the OpenID RISC (Risk and Incident Sharing and Coordination)
		working group <xref target="RISC"/>.
		The example is subject to change.
	      </preamble>
	      <artwork>
{
  "iss": "https://idp.example.com/",
  "jti": "756E69717565206964656E746966696572",
  "iat": 1508184845,
  "aud": "636C69656E745F6964",
  "events": {
    "http://schemas.openid.net/secevent/risc/event-type/\
    account-disabled": {
      "subject": {
        "subject_type": "iss-sub",
        "iss": "https://idp.example.com/",
        "sub": "7375626A656374"
      },
      "reason": "hijacking",
      "cause-time": 1508012752
    }
  }
}
</artwork>
	    </figure>
	  </t>
	  <t>
	    Notice that parameters to the event are included in the event payload, in this case,
	    the <spanx style="verb">reason</spanx> and <spanx style="verb">cause-time</spanx> values.
	    The subject of the event is identified using the <spanx style="verb">subject</spanx>
	    payload value, which itself is a JSON object.
          </t>

	</section>

      </section>

      <section anchor="EventContents" title="Core SET Claims">
        <t>
	  The following claims from <xref target="RFC7519"/> are profiled for use in SETs:
	  <list style="hanging">

            <t hangText='"iss" (Issuer) Claim'>
	      <vspace/>
	      As defined by Section 4.1.1 of <xref target="RFC7519"/>,
	      this claim contains a string identifying the service provider publishing
	      the SET (the issuer).
	      In some cases, the issuer of the SET will not be
	      the issuer associated with the security subject of the SET.
	      Therefore, implementers cannot assume that the issuers are the same
	      unless the profiling specification specifies that they are
	      for SETs conforming to that profile.
	      This claim is REQUIRED.
	    </t>

            <t hangText='"iat" (Issued At) Claim'>
	      <vspace/>
	      As defined by Section 4.1.6 of <xref target="RFC7519"/>,
	      this claim contains a value representing when the SET was issued.
	      This claim is REQUIRED.
            </t> 

            <t hangText='"jti" (JWT ID) Claim'>
	      <vspace/>
	      As defined by Section 4.1.7 of <xref target="RFC7519"/>,
	      this claim contains a unique identifier for the SET.
	      The identifier MUST be unique within
	      a particular event feed and MAY be used by clients to track
	      whether a particular SET has already been received.
	      This claim is REQUIRED.
	    </t>

            <t hangText='"aud" (Audience) Claim'>
	      <vspace/>
	      As defined by Section 4.1.3 of <xref target="RFC7519"/>,
	      this claim contains one or more audience identifiers for the SET.
	      This claim is RECOMMENDED.
	    </t>

            <!-- Removed after WGLC discussion
            <t hangText='"nbf" (Not Before) Claim'>
	    <vspace/>
	    Defined by 
            Section 4.1.5 of <xref target="RFC7519"/>, this claim is
            not used in SET and SHOULD NOT be used.</t>
             -->
             
            <t hangText='"sub" (Subject) Claim'>
      	      <vspace/>
      	      As defined by Section 4.1.2 of <xref target="RFC7519"/>,
      	      this claim contains a StringOrURI value representing
      	      the principal that is the subject of the SET. This is 
            usually the entity whose "state" was changed. 
            For example: <list style="symbols">
              <t>an IP Address was added to a black list;</t>
              <t>a URI representing a user resource that was modified; or,</t>
              <t>a token identifier (e.g. <spanx style="verb">jti</spanx>) 
              for a revoked token.</t>
            </list>
            If used, the profiling specification MUST define the 
            content and format semantics for the value. This claim
            is OPTIONAL, as the principal for any given profile may 
            already be identified without the inclusion of a subject 
            claim. Note that some SET profiles MAY choose to convey 
            event subject information in the event payload (either 
            using the <spanx style="verb">sub</spanx> member name or 
            another name), particularly if the subject information is
    	        relative to issuer information that is also conveyed in 
            the event payload, which may be the case for some identity 
            SET profiles.
      	      </t>   
      
            <t hangText='"exp" (Expiration Time) Claim'>
	      <vspace/>
	      As defined by Section 4.1.4 of <xref target="RFC7519"/>, this claim
	      is the time after which the JWT MUST NOT be accepted for processing.
	      In the context of a SET however, this notion does not typically apply,
	      since a SET represents something that has already occurred and is historical in nature.
	      Therefore, its use is NOT RECOMMENDED.
	      (Also, see <xref target="SETsAndIDTokens"/> for additional reasons
	      not to use the <spanx style="verb">exp</spanx> claim in some SET use cases.)
	    </t>

          </list>
        </t>

        <t>
	  The following new claims are defined by this specification:
	  <list style="hanging">

            <t hangText='"events" (Security Events) Claim' anchor="eventDef">
	      <vspace/>
	      This claim contains a set of event statements
	      that each provide information describing a single
	      logical event that has occurred about a security subject
	      (e.g., a state change to the subject).
	      Multiple event identifiers with the same value MUST NOT be used.
	      The <spanx style="verb">events</spanx>
	      claim MUST NOT be used to express multiple independent logical events.
	    </t>
            <t>
	      The value of the <spanx style="verb">events</spanx> claim is a
	      JSON object whose members are name/value pairs
	      whose names are URIs identifying the event statements being 
	      expressed. Event identifiers SHOULD be stable values (e.g., a
	      permanent URL for an event specification). For each name present, 
	      the corresponding value 
	      MUST be a JSON object. The JSON object MAY be an empty 
	      object (<spanx style="verb">{}</spanx>), or it MAY be a JSON 
	      object containing data described by the profiling specification.
	    </t>

            <t hangText='"txn" (Transaction Identifier) Claim' anchor="txnDef">
	      <vspace/>
	      An OPTIONAL string value that represents a unique transaction identifier.
	      In cases in which multiple related JWTs are issued, the transaction
	      identifier claim can be used to correlate these related JWTs.
	      Note that this claim can be used in JWTs that are SETs
	      and also in JWTs using non-SET profiles.
	    </t>

            <t hangText='"toe" (Time of Event) Claim'>
	      <vspace/>
	      A value that represents the date and time at which the event occurred.
	      This value is a NumericDate (see Section 2 of <xref target="RFC7519"/>).
	      By omitting this claim, the issuer indicates that
	      they are not sharing an event time with the recipient.
	      (Note that in some use cases, the represented time might be approximate;
	      statements about the accuracy of this field MAY be made by profiling specifications.)
	      This claim is OPTIONAL.
	    </t>

	  </list>
	</t>
      </section>

      <section anchor="ExplicitTyping" title="Explicit Typing of SETs">
	<t>
	  This specification registers the <spanx style="verb">application/secevent+jwt</spanx>
	  media type, which can be used to indicate that the content is a SET.
	  SETs MAY include this media type in the <spanx style="verb">typ</spanx> header parameter
	  of the JWT representing the SET to explicitly declare that the JWT is a SET.
	  This MUST be included if the SET could be used in an application context in which
	  it could be confused with other kinds of JWTs.
	</t>
	<t>
	  Per the definition of <spanx style="verb">typ</spanx> in Section 4.1.9 of <xref target="RFC7515"/>,
	  it is RECOMMENDED that the "application/" prefix be omitted.
	  Therefore, the <spanx style="verb">typ</spanx> value used SHOULD be
	  <spanx style="verb">secevent+jwt</spanx>.
	</t>
      </section>

      <section anchor="eventMessage" title="Security Event Token Construction">
        <t>
	  This section describes how to construct a SET.
	</t>

        <t>
	  <figure anchor="exampleJsonEvent" title="Example Event Claims">
            <preamble>
	      The following is an example JWT Claims Set for a hypothetical SCIM SET
	      (which has been formatted for readability):
	    </preamble>

            <artwork>
{  
  "iss": "https://scim.example.com",  
  "iat": 1458496404,
  "jti": "4d3559ec67504aaba65d40b0363faad8",
  "aud": [
   "https://scim.example.com/Feeds/98d52461fa5bbc879593b7754",
   "https://scim.example.com/Feeds/5d7604516b1d08641d7676ee7"
  ],  
  
  "events": {
    "urn:ietf:params:scim:event:create": {
      "ref":
        "https://scim.example.com/Users/44f6142df96bd6ab61e7521d9",
      "attributes": ["id", "name", "userName", "password", "emails"]
    }
  }
}
</artwork>
          </figure></t>

        <t>
	  The JSON Claims Set is encoded per <xref target="RFC7519"/>.
	</t>
     
        <t>
	  <figure>
            <preamble>
	      In this example, the SCIM SET claims are encoded in an unsecured JWT.
	      The JOSE Header for this example is:
	    </preamble>

            <artwork>{"typ":"secevent+jwt","alg":"none"}</artwork>
          </figure>
	</t>
	<t>
	  <figure>
            <preamble>Base64url encoding (see Section 2 of <xref target="RFC7515"/>) of the octets of the UTF-8
            <xref target="RFC3629"/> representation of the JOSE Header yields:</preamble>

            <artwork>eyJ0eXAiOiJzZWNldmVudCtqd3QiLCJhbGciOiJub25lIn0</artwork>
          </figure>
	</t>
	<t>
	  <figure>
            <preamble>The above example JWT Claims Set is encoded as
            follows:</preamble>

            <artwork>
eyJqdGkiOiI0ZDM1NTllYzY3NTA0YWFiYTY1ZDQwYjAzNjNmYWFkOCIsImlhdCI6MTQ1
ODQ5NjQwNCwiaXNzIjoiaHR0cHM6Ly9zY2ltLmV4YW1wbGUuY29tIiwiYXVkIjpbImh0
dHBzOi8vc2NpbS5leGFtcGxlLmNvbS9GZWVkcy85OGQ1MjQ2MWZhNWJiYzg3OTU5M2I3
NzU0IiwiaHR0cHM6Ly9zY2ltLmV4YW1wbGUuY29tL0ZlZWRzLzVkNzYwNDUxNmIxZDA4
NjQxZDc2NzZlZTciXSwiZXZlbnRzIjp7InVybjppZXRmOnBhcmFtczpzY2ltOmV2ZW50
OmNyZWF0ZSI6eyJyZWYiOiJodHRwczovL3NjaW0uZXhhbXBsZS5jb20vVXNlcnMvNDRm
NjE0MmRmOTZiZDZhYjYxZTc1MjFkOSIsImF0dHJpYnV0ZXMiOlsiaWQiLCJuYW1lIiwi
dXNlck5hbWUiLCJwYXNzd29yZCIsImVtYWlscyJdfX19</artwork>
          </figure>
	</t>
	<t>
          <figure anchor="eventToken"
            title="Example Unsecured Security Event Token">
            <preamble>The encoded JWS signature is the empty string.
            Concatenating the parts yields this complete SET:</preamble>

            <artwork>
eyJ0eXAiOiJzZWNldmVudCtqd3QiLCJhbGciOiJub25lIn0.
eyJqdGkiOiI0ZDM1NTllYzY3NTA0YWFiYTY1ZDQwYjAzNjNmYWFkOCIsImlhdCI6MTQ1
ODQ5NjQwNCwiaXNzIjoiaHR0cHM6Ly9zY2ltLmV4YW1wbGUuY29tIiwiYXVkIjpbImh0
dHBzOi8vc2NpbS5leGFtcGxlLmNvbS9GZWVkcy85OGQ1MjQ2MWZhNWJiYzg3OTU5M2I3
NzU0IiwiaHR0cHM6Ly9zY2ltLmV4YW1wbGUuY29tL0ZlZWRzLzVkNzYwNDUxNmIxZDA4
NjQxZDc2NzZlZTciXSwiZXZlbnRzIjp7InVybjppZXRmOnBhcmFtczpzY2ltOmV2ZW50
OmNyZWF0ZSI6eyJyZWYiOiJodHRwczovL3NjaW0uZXhhbXBsZS5jb20vVXNlcnMvNDRm
NjE0MmRmOTZiZDZhYjYxZTc1MjFkOSIsImF0dHJpYnV0ZXMiOlsiaWQiLCJuYW1lIiwi
dXNlck5hbWUiLCJwYXNzd29yZCIsImVtYWlscyJdfX19. 
</artwork>
          </figure></t>

        <t>For the purpose of having a simpler example in <xref target="eventToken"/>, 
        an unsecured token is shown. When SETs are not signed or
        encrypted, other mechanisms such as TLS MUST be employed
	to provide integrity protection, confidentiality,
	and issuer authenticity, as needed by the application.
        </t>
        <t>When validation (i.e., auditing), or additional transmission
        security is required, JWS signing and/or JWE encryption MAY be used. 
        To create and or validate a signed and/or encrypted SET, follow
        the instructions in Section 7 of <xref target="RFC7519"/>.</t>
      </section>
    </section>

    <section anchor="Profiles" title="Requirements for SET Profiles">
       <t>
  Profiling specifications of this specification define actual SETs 
  to be used in particular use cases. These profiling 
  specifications define the syntax and semantics of SETs conforming 
  to that SET profile and rules for validating those SETs.
      
  Profiling specifications SHOULD define syntax, semantics, subject 
  identification, and validation.<list style="hanging">
    
    <t hangText="Syntax"><vspace/>
    The syntax of the SETs defined, including:  
    <list style="hanging">
      <t hangText="Top-Level Claims"><vspace/>Claims and values 
      placed at the JWT Claims Set. Examples are claims
      defined by the JWT specification (see <xref target="RFC7519"/>),
      the SET specification, and by the profiling specification.</t>
      
      <t hangText="Event Payload"><vspace/>The JSON data structure
      contents and format, containing event-specific information,
      if any (see <xref target="defs"/>).</t>
    </list></t>
  
    <t hangText="Semantics"><vspace/> 
  Defining the semantics of the SET contents for SETs utilizing 
  the profile is equally important. Possibly most important is 
  defining the procedures used to validate the SET issuer
  and to obtain the keys controlled by the issuer that were used for
  cryptographic operations used in the JWT representing the SET.
  For instance, some profiles may define an algorithm for retrieving
  the SET issuer's keys that uses the <spanx style="verb">iss</spanx> 
  claim value as its input. Likewise, if the profile allows (or 
  requires) that the JWT be unsecured, the means by which the 
  integrity of the JWT is ensured MUST be specified.
    </t>
  
    <t hangText="Subject Identification"><vspace/>
  Profiling specifications MUST define how the event subject is identified in the SET,
  as well as how to differentiate between the event subject's issuer and the SET issuer, if applicable.
  It is NOT RECOMMENDED for profiling specifications to use the <spanx style="verb">sub</spanx> claim
  in cases in which the subject is not globally unique and has a different issuer from the SET itself.
    </t>
  
    <t hangText="Validation"><vspace/>
  Profiling specifications MUST clearly specify the steps that a recipient of a SET
  utilizing that profile MUST perform to validate that the SET is
  both syntactically and semantically valid.
    </t>
    <t> 
  Among the syntax and semantics of SETs that a profiling specification 
  may define is whether the value of the <spanx style="verb">events</spanx>  
  claim may contain multiple members, and what processing instructions 
  are employed in the single- and multiple-valued cases for SETs 
  conforming to that profile.  Many valid choices are possible.
  For instance, some profiles might allow multiple event identifiers to be present
  and specify that any that are not understood by recipients be ignored,
  thus enabling extensibility.
  Other profiles might allow multiple event identifiers to be present
  but require that all be understood if the SET is to be accepted.
  Some profiles might require that only a single value be present.
  All such choices are within the scope of profiling specifications to define.</t>
  </list></t>
    </section>

    <section anchor="SETsAndJWTs" title="Preventing Confusion between SETs and other JWTs">
      <t>
	  Because <xref target="RFC7519"/> states that "all claims that are not understood
	  by implementations MUST be ignored", there is a consideration that 
	  a SET might be confused with another kind of JWT from the same issuer.
	  Unless this confusion is prevented, this might enable an attacker who possesses
	  a SET to use it in a context in which another kind of JWT is expected, or vice-versa.
	  This section presents concrete techniques for preventing confusion between
	  SETs and several other specific kinds of JWTs, as well as generic techniques
	  for preventing possible confusion between SETs and other kinds of JWTs.
      </t>

      <section anchor="SETsAndIDTokens" title="Distinguishing SETs from ID Tokens">
        <t>
	  A SET might be confused with ID Token <xref target="OpenID.Core"/>
	  if a SET is mistakenly or maliciously used in a context requiring an ID Token.
	  If a SET could otherwise be interpreted as a valid ID Token
	  (because it includes the required claims for an ID Token
	  and valid issuer and audience claim values for an ID Token)
	  then that SET profile MUST require that the <spanx style="verb">exp</spanx> claim
	  not be present in the SET.
	  Because <spanx style="verb">exp</spanx> is a required claim in ID Tokens,
	  valid ID Token implementations will reject such a SET if presented as if it were an ID Token.
	</t>
	<t>
	  Excluding <spanx style="verb">exp</spanx> from SETs that
	  could otherwise be confused with ID Tokens is actually defense in depth.
	  In any OpenID Connect contexts in which an attacker could attempt to substitute a SET for an ID Token,
	  the SET would actually already be rejected as an ID Token
	  because it would not contain the correct <spanx style="verb">nonce</spanx> claim value
	  for the ID Token to be accepted in contexts for which substitution is possible.
	</t>
	<t>
	  Note that the use of explicit typing, as described in <xref target="ExplicitTyping"/>,
	  will not achieve disambiguation between ID Tokens and SETs, as the ID Token validation rules
	  do not use the <spanx style="verb">typ</spanx> header parameter value.
	</t>
      </section>

      <section anchor="SETsAndATs" title="Distinguishing SETs from Access Tokens">
	<t>
	  OAuth 2.0 <xref target="RFC6749"/> defines access tokens as being opaque.
	  Nonetheless, some implementations implement access tokens as JWTs.
	  Because the structure of these JWTs is implementation-specific,
	  ensuring that a SET cannot be confused with such an access token is therefore
	  likewise, in general, implementation specific.
	  Nonetheless, it is recommended that SET profiles employ the following strategies
	  to prevent possible substitutions of SETs for access tokens
	  in contexts in which that might be possible:
	  <list style="symbols">
	    <t>
	      Prohibit use of the <spanx style="verb">exp</spanx> claim,
	      as is done to prevent ID Token confusion.
	    </t>
	    <t>
	      Where possible, use a separate <spanx style="verb">aud</spanx>
	      claim value to distinguish between the SET recipient and the 
	      protected resource that is the audience of an access token.
	    </t>
	    <t>
	      Modify access token validation systems to check for the presence of 
	      the <spanx style="verb">events</spanx> claim as a means to detect
	      security event tokens. This is particularly useful if the same endpoint
	      may receive both types of tokens.
	    </t>
	    <t>
	      Employ explicit typing, as described in <xref target="ExplicitTyping"/>,
	      and modify access token validation systems to use the
	      <spanx style="verb">typ</spanx> header parameter value.
	    </t>
	  </list>
	</t>
      </section>

      <section anchor="SETsAndOtherJWTs" title="Distinguishing SETs from other kinds of JWTs">
	<t>
	  JWTs are now being used in application areas beyond the identity applications
	  in which they first appeared. For instance, the 
	  "Session Initiation Protocol (SIP) Via Header Field Parameter
	  to Indicate Received Realm" <xref target="RFC8055"/>
	  and
	  "Personal Assertion Token (PASSporT)" <xref target="RFC8225"/>
	  specifications both define JWT profiles that use mostly or completely different sets of claims
	  than are used by ID Tokens.
	  If it would otherwise be possible for an attacker to substitute a SET for one of these (or other)
	  kinds of JWTs, then the SET profile must be defined in such a way that any substituted SET
	  will result in its rejection when validated as the intended kind of JWT.
	</t>
	<t>
	  The most direct way to prevent confusion is to
	  employ explicit typing, as described in <xref target="ExplicitTyping"/>,
	  and modify applicable token validation systems to use the
	  <spanx style="verb">typ</spanx> header parameter value.
	  This approach can be employed for new systems but may not be applicable to existing systems.
	</t>
	<t>
	  Another way to ensure that a SET is not confused with another kind of JWT
	  is to have the JWT validation logic reject JWTs containing an <spanx style="verb">events</spanx> claim
	  unless the JWT is intended to be a SET.
	  This approach can be employed for new systems but may not be applicable to existing systems.
	  Validating that the JWT has an <spanx style="verb">events</spanx> claim will be effective
	  in preventing attackers from passing other kinds of JWTs off as SETs.
	</t>
	<t>
	  For many use cases, the simplest way to prevent substitution is requiring that the SET not include
	  claims that are required for the kind of JWT that might be the target of an attack.
	  For example, for <xref target="RFC8055"/>,
	  the <spanx style="verb">sip_callid</spanx> claim could be omitted
	  and for <xref target="RFC8225"/>,
	  the <spanx style="verb">orig</spanx> claim could be omitted.
	</t>
	<t>
	  In many contexts, simple measures such as these will accomplish the task,
	  should confusion otherwise even be possible.
	  Note that this topic is being explored in a more general fashion in
	  JSON Web Token Best Current Practices <xref target="I-D.ietf-oauth-jwt-bcp"/>.
	  The proposed best practices in that draft may also be applicable
	  for particular SET profiles and use cases.
	</t>
      </section>
    </section>

    <section anchor="Security" title="Security Considerations" toc="default">
      
      <section anchor="ConfidentialityIntegrity" title="Confidentiality and Integrity">

      <t>SETs may contain sensitive information. Therefore,
      methods for distribution of events SHOULD require the use of a 
      transport-layer security mechanism when distributing events. 
      Parties MUST support TLS 1.2 <xref target="RFC5246"/> or a higher version and MAY support
      additional transport-layer mechanisms meeting its security
      requirements. When using TLS, the client MUST perform a TLS server
      certificate check, per <xref target="RFC6125"/>. Implementation
      security considerations for TLS can be found in "Recommendations for
      Secure Use of TLS and DTLS" <xref target="RFC7525"/>.</t>
      
      <t>Security events distributed through third parties or that carry personally
      identifiable information MUST be encrypted using JWE <xref target="RFC7516"/>
      or secured for confidentiality by other means.
      </t>

      <t>Unless integrity of the JWT is ensured by other means, it
      MUST be signed using JWS <xref target="RFC7515"/>
      by an issuer that is trusted to do so for the use case so
      that the SET can be authenticated and validated by the 
      SET recipient.</t>

      </section>

      <section anchor="Delivery" title="Delivery">

      <t>This specification does not define a delivery mechanism for SETs.
      In addition to confidentiality and integrity (discussed above), implementers
      and profiling specifications must consider the consequences of delivery 
      mechanisms that are not secure and/or not assured. For example, while
      a SET may be end-to-end secured using JWE encrypted SETs, without (mutual) TLS,
      there is no assurance that the correct endpoint received the SET and 
      that it could be successfully processed.</t>
      </section>
      
      <section anchor="Sequencing" title="Sequencing">

        <t>
	  This specification defines no means of ordering multiple SETs in a sequence.
	  Depending on the type and nature of the events represented by SETs,
	order may or may not matter. For example, in provisioning, 
        event order is critical -- an object cannot be modified before it
        is created. In other SET types, such as a token revocation, the order
        of SETs for revoked tokens does not matter. If, however, the event conveys
        a logged in or logged out status for a user subject, then
        order becomes important.</t>

        <t>Profiling specifications and implementers SHOULD take caution when
        using timestamps such as <spanx style="verb">iat</spanx> to define order. Distributed systems will have 
        some amount of clock skew. Thus, time by itself will not guarantee order.</t>
        
        <t>Specifications profiling SET SHOULD define a mechanism for detecting
        order or sequence of events when the order matters.
	For example, the <spanx style="verb">txn</spanx>
        claim could contain an ordered value (e.g., a counter) that the issuer includes,
	  although just as for timestamps,
	  ensuring such ordering can be difficult in distributed systems.
	</t>
      </section>
      
      <section anchor="Timing" title="Timing Issues">

        <t>When SETs are delivered asynchronously and/or out-of-band 
        with respect to the original action that incurred the 
        security event, it is important to consider that a SET 
        might be delivered to a SET recipient in advance of
        or behind the process that caused the event. For example, 
        a user having been required to log out and then log back 
        in again, may cause a "token revoked" SET to be issued,
        typically causing the receiver to reset all active 
        sessions at the receiver that are related to that user. 
        If revocation SET arrives at the same time as the user 
        agent re-logs in, timing could cause problems by 
        erroneously treating the new user session as logged out. 
        Profiling specifications SHOULD be careful to consider 
        both SET expression and timing issues. For example, it 
        might be more appropriate to revoke a specific session or 
        identity token rather than a general logout statement 
        about a "user". Alternatively, profiling specifications 
        could use timestamps that allow new sessions to be started 
        immediately after a stated logout event time.</t>
      </section>

      <section anchor="ConfusionConsiderations" title="Preventing Confusion">
	<t>
	  Also, see <xref target="SETsAndJWTs"/> above for both additional security considerations
	  and normative text on preventing SETs from being confused with other kinds of JWTs.
	</t>
      </section>

    </section>
    
    <section anchor="Privacy" title="Privacy Considerations">
    
      <t>If a SET needs to be retained for audit purposes, the signature can
      be used to provide verification of its authenticity.</t>
      
      <t>SET issuers SHOULD attempt to specialize SETs so that their content
      is targeted to the specific business and protocol needs of 
      the intended SET recipients.</t>
      
      <t>When sharing personally identifiable information or information
      that is otherwise considered confidential to affected users,
      SET issuers and recipients should have the appropriate legal agreements
      and user consent and/or terms of service in place.</t>
      
      <t>The propagation of subject identifiers can be perceived as personally
      identifiable information. Where possible, SET issuers and recipients
      SHOULD devise approaches that prevent propagation -- for example, the
      passing of a salted hash value that requires the SET recipient to know
      the subject.</t>

      <t>
	In some cases, it may be possible for a SET recipient to correlate different events
	and thereby gain information about a subject that the SET issuer did not intend to share.
	For example, a SET recipient might be able to use <spanx style="verb">iat</spanx> values
	or highly precise <spanx style="verb">toe</spanx> values to determine that
	two otherwise un-relatable events actually relate to the same real-world event.
	The union of information from both events could allow a SET recipient to de-anonymize data
	or recognize that unrelated identifiers relate to the same individual.
	SET issuers SHOULD take steps to minimize the chance of event correlation,
	when such correlation would constitute a privacy violation.
	For instance, they could use approximate values for the <spanx style="verb">toe</spanx> claim
	or arbitrarily delay SET issuance, where such delay can be tolerated.
      </t>
    </section>

    <section anchor="IANA" title="IANA Considerations">

      <section anchor="ClaimsRegistry" title="JSON Web Token Claims Registration">
	<t>
	  This specification registers the <spanx style="verb">events</spanx>,
    <spanx style="verb">toe</spanx>, and
	  <spanx style="verb">txn</spanx> claims in the IANA
	  "JSON Web Token Claims" registry <xref target="IANA.JWT.Claims"/>
	  established by <xref target="RFC7519"/>.
	</t>

	<section anchor='ClaimsContents' title='Registry Contents'>
	  <t>
	    <?rfc subcompact="yes"?>
	    <list style='symbols'>
	      <t>
		Claim Name: <spanx style="verb">events</spanx>
	      </t>
	      <t>
		Claim Description: Security Events
	      </t>
	      <t>
		Change Controller: IESG
	      </t>
	      <t>
		Specification Document(s): <xref target="EventContents"/> of [[ this specification ]]
	      <vspace blankLines="1"/></t>
	      
	       <t>
    Claim Name: <spanx style="verb">toe</spanx>
        </t>
        <t>
    Claim Description: Time of Event
        </t>
        <t>
    Change Controller: IESG
        </t>
        <t>
    Specification Document(s): <xref target="EventContents"/> of [[ this specification ]]
        <vspace blankLines="1"/></t>
        
        <t>
		Claim Name: <spanx style="verb">txn</spanx>
	      </t>
	      <t>
		Claim Description: Transaction Identifier
	      </t>
	      <t>
		Change Controller: IESG
	      </t>
	      <t>
		Specification Document(s): <xref target="EventContents"/> of [[ this specification ]]
	      </t>
	    </list>
	  </t>
	</section>
	<?rfc subcompact="no"?>
      </section>

      <section title="Structured Syntax Suffix Registration" anchor="SuffixReg">
	<t>
	  This section registers the <spanx style="verb">+jwt</spanx>
	  structured syntax suffix <xref target="RFC6838"/>
	  in the "Structured Syntax Suffix" registry <xref target="IANA.StructuredSuffix"/>
	  in the manner described in <xref target="RFC6838"/>,
	  which can be used to indicate that the media type is encoded as a JWT.
	</t>
	<section title="Registry Contents" anchor="SuffixContents">
	  <t>
	    <?rfc subcompact="yes"?>
	    <list style="symbols">
	      <t>
		Name: JSON Web Token (JWT)
	      </t>
	      <t>
		+suffix: +jwt
	      </t>
	      <t>
		References: Section 3 of <xref target="RFC7519"/>
	      </t>
	      <t>
		Encoding considerations: binary;
		JWT values are encoded as a
		series of base64url-encoded values (some of which may be the
		empty string) separated by period ('.') characters.
	      </t>
	      <t>
		Interoperability considerations: n/a
	      </t>
	      <t>
		Fragment identifier considerations:
		<vspace/>
		The syntax and semantics of fragment identifiers specified for
		+jwt SHOULD be as specified for "application/jwt".  (At
		publication of this document, there is no fragment identification
		syntax defined for "application/jwt".)
		<vspace blankLines="1"/>
		The syntax and semantics for fragment identifiers for a specific
		"xxx/yyy+jwt" SHOULD be processed as follows:
		<vspace blankLines="1"/>
		For cases defined in +jwt, where the fragment identifier resolves
		per the +jwt rules, then process as specified in +jwt.
		<vspace blankLines="1"/>
		For cases defined in +jwt, where the fragment identifier does not
		resolve per the +jwt rules, then process as specified in
		"xxx/yyy+jwt".
		<vspace blankLines="1"/>
		For cases not defined in +jwt, then process as specified in
		"xxx/yyy+jwt".
	      </t>
	      <t>
		Security considerations: See Section 11 of <xref target="RFC7519"/>.
	      </t>
	      <t>
		Contact:
		<vspace/>
		Michael B.&nbsp;Jones, mbj@microsoft.com
	      </t>
	      <t>
		Author/Change controller:
		<vspace/>
		Security Events Working Group.
		<vspace/>
		The IESG has change control over this registration.
	      </t>
	    </list>
	  </t>
	</section>
	<?rfc subcompact="no"?>
      </section>

      <section title="Media Type Registration" anchor="MediaReg">
	<section title="Registry Contents" anchor="MediaContents">
	  <t>
	    This section registers the <spanx style="verb">application/secevent+jwt</spanx>
	    media type <xref target="RFC2046"/>
	    in the "Media Types" registry <xref target="IANA.MediaTypes"/>
	    in the manner described in <xref target="RFC6838"/>,
	    which can be used to indicate that the content is a SET.
	  </t>
	  <t> <?rfc subcompact="yes"?>
	    <list style="symbols">
	      <t>
		Type name: application
	      </t>
	      <t>
		Subtype name: secevent+jwt
	      </t>
	      <t>
		Required parameters: n/a
	      </t>
	      <t>
		Optional parameters: n/a
	      </t>
	      <t>
		Encoding considerations: binary;
		A SET is a JWT;
		JWT values are encoded as a
		series of base64url-encoded values (some of which may be the
		empty string) separated by period ('.') characters.
	      </t>
	      <t>
		Security considerations: See <xref target="Security"/> of [[ this specification ]]
	      </t>
	      <t>
		Interoperability considerations: n/a
	      </t>
	      <t>
		Published specification: <xref target="ExplicitTyping"/> of [[ this specification ]]
	      </t>
	      <t>
		Applications that use this media type:
		Applications that exchange SETs
	      </t>
	      <t>
		Fragment identifier considerations: n/a
	      </t>
	      <t>
		Additional information:<list style="empty">
	        <t>Magic number(s): n/a</t>
		<t>File extension(s): n/a</t>
		<t>Macintosh file type code(s): n/a </t></list>
<vspace/>
	      </t>
	      <t>
		Person &amp; email address to contact for further information:
<vspace/>
		Michael B.&nbsp;Jones, mbj@microsoft.com
	      </t>
	      <t>
		Intended usage: COMMON
	      </t>
	      <t>
		Restrictions on usage: none
	      </t>
	      <t>
		Author: Michael B.&nbsp;Jones, mbj@microsoft.com
	      </t>
	      <t>
		Change controller: IESG
	      </t>
	      <t>
		Provisional registration? No
	      </t>
	    </list>
	  </t>
	</section>
	<?rfc subcompact="no"?>
      </section>
      
    </section>

  </middle>

  <back>
    <references title="Normative References">

    <!-- 
      <reference anchor="idevent-subscription">
        
        <front>
          <title>Identity Event Subscription Protocol (work in progress)</title>
          <author fullname="Phil Hunt"><organization>Oracle Corporation</organization></author>
          <date/>
        </front>  
      </reference>
       -->
       
      <?rfc include='http://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.2119.xml' ?><!-- Keywords -->
      <?rfc include='http://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.3629.xml'?><!-- UTF-8 -->
      <?rfc include='http://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.3986.xml'?><!-- URIs -->
      <?rfc include='http://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.5246.xml'?><!-- TLS 1.2 -->
      <?rfc include='http://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.6125.xml'?><!-- TLS Cert-->
      <?rfc include='http://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.6749.xml'?><!-- OAuth 2.0 -->
      <?rfc include='http://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.7515.xml'?><!-- JWS -->
      <?rfc include='http://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.7516.xml'?><!-- JWE -->
      <?rfc include='http://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.7519.xml'?><!-- JWT -->
      <?rfc include='http://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.7525.xml'?><!-- TLS BCP -->
      <?rfc include="http://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.8174.xml"?> <!--RFC 2119 bis-->

      <reference anchor="IANA.JWT.Claims" target="http://www.iana.org/assignments/jwt">
        <front>
          <title>JSON Web Token Claims</title>
          <author>
            <organization>IANA</organization>
          </author>
	  <date/>
        </front>
      </reference>

      <reference anchor="IANA.MediaTypes" target="http://www.iana.org/assignments/media-types">
        <front>
          <title>Media Types</title>
          <author>
            <organization>IANA</organization>
          </author>
	  <date/>
        </front>
      </reference>

      <reference anchor="IANA.StructuredSuffix" target="https://www.iana.org/assignments/media-type-structured-suffix/">
        <front>
          <title>Structured Syntax Suffix</title>
          <author>
            <organization>IANA</organization>
          </author>
	  <date/>
        </front>
      </reference>

    </references>
 
    <references title="Informative References">
      <?rfc include='http://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.2046.xml' ?><!-- MIME -->
      <?rfc include='http://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.6838.xml' ?><!-- MIME Registration -->
      <?rfc include='http://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.7644.xml'?><!-- SCIM Protocol -->
      <?rfc include='http://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.8055.xml'?><!-- SIP Via Header -->
      <?rfc include='http://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.8225.xml'?><!-- PASSporT -->

      <?rfc include="http://xml2rfc.tools.ietf.org/public/rfc/bibxml3/reference.I-D.draft-ietf-oauth-jwt-bcp-03.xml" ?>

       
      <reference anchor="OpenID.Core" target="http://openid.net/specs/openid-connect-core-1_0.html">
        <front>
          <title>OpenID Connect Core 1.0</title>
 
          <author fullname="Nat Sakimura" initials="N." surname="Sakimura">
            <organization abbrev="NRI">Nomura Research Institute, Ltd.</organization>
          </author>
 
          <author fullname="John Bradley" initials="J." surname="Bradley">
            <organization abbrev="Ping Identity">Ping Identity</organization>
          </author>
 
          <author fullname="Michael B. Jones" initials="M.B." surname="Jones">
            <organization abbrev="Microsoft">Microsoft</organization>
          </author>
 
          <author fullname="Breno de Medeiros" initials="B." surname="de Medeiros">
            <organization abbrev="Google">Google</organization>
          </author>
 
                <author fullname="Chuck Mortimore" initials="C." surname="Mortimore">
                  <organization abbrev="Salesforce">Salesforce</organization>
                </author>
 
          <date day="8" month="November" year="2014"/>
        </front>
      </reference>

      <reference anchor="OpenID.BackChannel" target="http://openid.net/specs/openid-connect-backchannel-1_0.html">
	<front>
	  <title>OpenID Connect Back-Channel Logout 1.0</title>

	  <author fullname="Michael B. Jones" initials="M.B." surname="Jones">
	    <organization abbrev="Microsoft">Microsoft</organization>
	  </author>

          <author fullname="John Bradley" initials="J." surname="Bradley">
            <organization abbrev="Ping Identity">Ping Identity</organization>
          </author>

	  <date day="25" month="January" year="2017" />
	</front>
      </reference>

      <reference anchor="RISC" target="http://openid.net/wg/risc/">
        <front>
          <title>OpenID Risk and Incident Sharing and Coordination (RISC) Working Group</title>
          <author> <organization>OpenID Foundation</organization></author>
          <date/>
        </front>
      </reference>

 <!-- 

      <reference anchor="HEART" target="http://openid.net/wg/heart/">
        <front>
          <title>OpenID Health Relationship Trust (HEART) Working Group</title>
          <author> <organization>OpenID Foundation</organization></author>
          <date/>
        </front>
      </reference>
      
 -->

    </references>

    <!-- <section anchor="Contributors" title="Contributors"/> Uncomment if and when this section is non-empty -->

    <section anchor="Acknowledgments" title="Acknowledgments">
      <t>The editors would like to thank the members of the IETF SCIM working group, which 
      began discussions of provisioning events starting with draft-hunt-scim-notify-00 in 2015.
      The editors would like to thank the participants in the IETF id-event
      mailing list, the Security Events working group,
      and related working groups for their contributions to this specification.
      The specification incorporates suggestions made by many people, including
      Annabelle Backman,
      John Bradley,
      Alissa Cooper,
      Ned Freed,
      Dick Hardt,
      Russ Housley,
      Benjamin Kaduk,
      Mirja Kuehlewind,
      Mark Lizar,
      Alexey Melnikov,
      Andrew Nash,
      Eric Rescorla,
      Adam Roach,
      Justin Richer,
      Nat Sakimura,
      Marius Scurtescu,
      Yaron Sheffer,
      and Martin Vigoureux.
      </t>
    </section>

    <section anchor="History" title="Change Log">

      <t>[[ to be removed by the RFC Editor before publication as an RFC ]]</t>

      <t>From the original draft-hunt-idevent-token:</t>
      <t>Draft 01 - PH - Renamed eventUris to events</t>
      <t>Draft 00 - PH - First Draft</t>
      <t>Draft 01 - PH - Fixed some alignment issues with JWT. Remove event type attribute.</t>
      <t>Draft 02 - PH - Renamed to Security Events, removed questions, clarified examples and intro text, and added security and privacy section.</t>
      <t>Draft 03 - PH <list style="symboles">
        <t>General edit corrections from Sarah Squire</t>
        <t>Changed "event" term to "SET"</t>
        <t>Corrected author organization for William Denniss to Google</t>
        <t>Changed definition of SET to be 2 parts, an envelope and 1 or more payloads.</t>
        <t>Clarified that the intent is to express a single event with optional extensions only.</t>
      </list>
                  - mbj - Registered <spanx style="verb">events</spanx> claim, and proof-reading corrections.</t> 
      <t>Draft 04 - PH - <list style="symbols">
        <t>Re-added the "sub" claim with clarifications that any SET type may use it.</t>
        <t>Added additional clarification on the use of envelope vs. payload attributes</t>
        <t>Added security consideration for event timing.</t>
        <t>Switched use of "attribute" to "claim" for consistency.</t>
        <t>Revised examples to put "sub" claim back in the top level.</t>
        <t>Added clarification that SETs typically do not use "exp".</t>
        <t>Added security consideration for distinguishing Access Tokens and SETs.</t>
      </list></t>
      
      <t>Draft 05 - PH - Fixed find/replace error that resulted in claim being spelled claimc</t>
      <t>Draft 06 - PH - <list style="symbols">
        <t>Corrected typos</t>
        <t>New txn claim</t>
        <t>New security considerations Sequencing and Timing Issues</t>
      </list></t>
      <t>
	Draft 07 -
	<list style="symbols">
	  <t>PH - Moved payload objects to be values of event URI attributes, per discussion.</t>
	  <t>mbj - Applied terminology consistency and grammar cleanups.</t>
	</list>
      </t>
      <t>Draft 08 - PH - <list style="symbols">
        <t>Added clarification to status of examples</t>
        <t>Changed from primary vs. extension to state that multiple 
        events may be expressed, some of which may or may not
        be considered extensions of others (which is for the subscriber 
        or profiling specifications to determine).</t>
        <t>Other editorial changes suggested by Yaron </t>
      </list></t>
      <t><vspace/>From draft-ietf-secevent-token:</t>
      <t>Draft 00 - PH - First WG Draft based on draft-hunt-idevent-token</t>
      <t>Draft 01 - PH - Changes as follows:<list style="symbols">
        <t>Changed terminology away from pub-sub to transmitter/receiver based on WG feedback</t>
        <t>Cleaned up/removed some text about extensions (now only used as example)</t>
        <t>Clarify purpose of spec vs. future profiling specs that define actual events</t>
      </list></t>
      <t>
	Draft 02 - Changes are as follows:
	<list style="symbols">
	  <t>
	    mbj -
	    Added the Requirements for SET Profiles section.
	  </t>
	  <t>
	    mbj -
	    Expanded the Security Considerations section to describe
	    how to prevent confusion of SETs with ID Tokens, access tokens,
	    and other kinds of JWTs.
	  </t>
	  <t>
	    mbj -
	    Registered the <spanx style="verb">application/secevent+jwt</spanx> media type
	    and defined how to use it for explicit typing of SETs.
	  </t>
	  <t>
	    mbj -
	    Clarified the misleading statement that used to say that
	    a SET conveys a single security event.
	  </t>
	  <t>
	    mbj -
	    Added a note explicitly acknowledging that some SET profiles
	    may choose to convey event subject information in the event payload.
	  </t>
	  <t>
	    PH -
	    Corrected encoded claim example on page 10.
	  </t>
	  <t>
	    mbj -
	    Applied grammar corrections.
	  </t>
	</list>
      </t>
  <t>Draft 03 - Changes are as follows:<list style="symbols">
    <t>pjh - Corrected old "subscriber" to "Event Receiver". Added clarification
    in definition that Event Receiver is the same as JWT recipient.</t>
    <t>pjh - Added definition for "toe" (and IANA registration).</t>
    <t>pjh - Removed "nbf" claim.</t>
    <t>pjh - Figure 3, moved "sub" to the events payload next to "iss".</t>
    <t>pjh - Clarified the use of "nonce" in contexts where substitution is possible.</t>
    <t>mbj - Addressed WGLC comments by Nat Sakimura.</t>
    <t>mbj - Addressed WGLC comments by Annabelle Backman.</t>
    <t>mbj - Addressed WGLC comments by Marius Scurtescu.</t>
  </list></t>

      <t>
	Draft 04 - mbj - Changes were as follows:
	<list style="symbols">
	  <t>
	    Clarified that all "events" values must represent aspects of the same state change
	    that occurred to the subject -- not an aggregation of unrelated events about the subject.
	  </t>
	  <t>
	    Removed ambiguities about the roles of multiple "events" values and
	    the responsibilities of profiling specifications for defining how and when they are used.
	  </t>
	  <t>
	    Corrected places where the term JWT was used when
	    what was actually being discussed was the JWT Claims Set.
	  </t>
	  <t>
	    Addressed terminology inconsistencies.  In particular,
	    standardized on using the term "issuer" to align with JWT terminology and the "iss" claim.
	    Previously the term "transmitter" was sometimes used and "issuer" was sometimes used.
	    Likewise, standardized on using the term "recipient" instead of "receiver" for the same reasons.
	  </t>
	  <t>
	    Added a RISC event example, courtesy of Marius Scurtescu.
	  </t>
	  <t>
	    Applied wording clarifications suggested by Annabelle Backman and Yaron Sheffer.
	  </t>
	  <t>
	    Applied numerous grammar, syntax, and formatting corrections.
	  </t>
	</list>
      </t>

      <t>
	Draft 05 - mbj - Changes were as follows:
	<list style="symbols">
	  <t>
	    Simplified the definitions of the "iat" and "toe" claims in ways suggested by Annabelle Backman.
	  </t>
	  <t>
	    Added privacy considerations text suggested by Annabelle Backman.
	  </t>
	  <t>
	    Updated the RISC event example, courtesy of Marius Scurtescu.
	  </t>
	  <t>
	    Reordered the claim definitions to place the required claims first.
	  </t>
	  <t>
	    Changed to using the RFC 8174 boilerplate instead of the RFC 2119 boilerplate.
	  </t>
	</list>
      </t>

      <t>
	Draft 06 - mbj - Changes were as follows:
	<list style="symbols">
	  <t>
	    Changed "when the event was issued" to "when the SET was issued"
	    in the "iat" description, as suggested by Annabelle Backman.
	  </t>
	  <t>
	    Applied editorial improvements that improve the consistency of the specification
	    that were suggested by Annabelle Backman, Marius Scurtescu, and Yaron Sheffer.
	  </t>
	</list>
      </t>
       
      <t>Draft 07 - PH - Text refinement to Section 3 proposed by Annabelle Backman post WGLC</t>

      <t>
	Draft 08 - mbj - Changes were as follows:
	<list style="symbols">
	  <t>
	    Incorporated wording improvements resulting from Russ Housley's SecDir comments.
	  </t>
	  <t>
	    Acknowledged individuals who made significant contributions.
	  </t>
	</list>
      </t>

      <t>Draft 09 - pjh/mbj - Changes addressing AD review comments by Benjamin Kaduk</t>

      <t>
	Draft 10 - pjh/mbj - Changes were as follows:
	<list style="symbols">
	  <t>
	    Incorporated wording improvements resulting from Russ Housley's additional SecDir comments.
	  </t>
	  <t>
	    Registered +jwt structured syntax suffix.
	  </t>
	</list>
      </t>
      <t>
	Draft 11 - pjh/mbj - Incorporated feedback from Security Area Director Eric Rescorla and IANA Designated Expert Ned Freed.
	<list style="symbols">
	  <t>
	    Clarified "iss" claim language about the SET issuer versus the security subject issuer.
	  </t>
	  <t>
	    Changed a "SHOULD" to a "MUST" in the "sub" claim description to be consistent with the Requirements for SET Profiles section.
	  </t>
	  <t>
	    Described the use of the "events" claim to prevent attackers from passing off other kinds of JWTs as SETs.
	  </t>
	  <t>
	    Stated that SETs are to be signed by an issuer that is trusted to do so for the use case.
	  </t>
	  <t>
	    Added quotes in the phrase '"token revoked" SET to be issued' in the Timing Issues section.
	  </t>
	  <t>
	    Added section number references to the media type and media type suffix registrations.
	  </t>
	  <t>
	    Changed the encodings of the media type and media type suffix registrations to binary (since no line breaks are allowed).
	  </t>
	  <t>
	    Replaced a "TBD" in the media type registration with descriptive text.
	  </t>
	  <t>
	    Acknowledged Eric Rescorla and Ned Freed.
	  </t>
	</list>
      </t>
      <t>Draft 12 - pjh/mbj - Incorporated feedback from Adam Roach, Alexey Melnikov, and Alissa Cooper.
      <list style="symbols">
        <t>Removed unused references to RFC 7009 and RFC 7517.</t>
        <t>Corrected name of RFC 8055 in Section 4.3 to "Session Initiation Protocol (SIP) Via Header Field Parameter to Indicate Received Realm".</t>
        <t>Added normative references for base64url and UTF-8.</t>
        <t>Section 5.1 - Changed SHOULD to MUST in "personally identifiable information MUST be encrypted using JWE [RFC7516] or ...".</t>
        <t>Section 5.2 - Changed "MUST consider" to "must consider".</t>
      </list></t>
      
      <t>Draft 13 - ph - Added edit from Martin Vigoureaux regarding a non-normative "MAY" in Section 1.1. Updated acknowledgements.</t>
    </section>
  </back>
</rfc>